On Thursday, Sadler attempted to make a joke about Senator John McCain's opposition to Central Intelligence Agency nominee Gina Haspel by saying "he's dying anyway", an attempt at humor that reportedly "fell flat".
In the meeting with communications staffers, Sanders called the comment by special assistant Kelly Sadler "unacceptable", according to ABC News, but sources told the network she was more upset over the leak of the remark.
"Her refusal to acknowledge torture's immorality is disqualifying", McCain wrote in a statement.
According to The Hill, sources have said that Sadler was joking and meant no harm but her humor fell flat with other officials at the internal White House meeting. She also took the opportunity to reflect on her belief that the tone of the White House staff is set by its leader, President Trump. McCain, meanwhile, has been one of the president's most prominent Republican critics and apparently does not want Trump at his funeral. "It doesn't matter", Ms. Sadler said, "He's dying anyway".
Sen. Lindsey Graham on Saturday called a White House aide's attack on Sen.
McCain's daughter Meghan responded Friday morning to the quip. John McCain, calling him a "songbird" for his five years spent a prisoner of war in Vietnam.
"People have wondered when decency would hit rock bottom with this administration".
The conversation turned to Mr. McCain's opposition to Mr. Trump's nominee for C.I.A. director because of her past ties to an interrogation program that used torture on terrorist suspects.
The New York Times reported last weekend that McCain's associates had informed the White House that they do not plan to give Trump a speaking role at his funeral, to be held at Washington National Cathedral, but that Vice President Mike Pence would be welcome to attend.
McCain is now battling an aggressive form of brain cancer.
"My dad's about character and bipartisanship and something greater than yourself, and believing in this country and believing in the fact that we as Americans can still come together", she said. "John McCain's going to have a hell of a legacy".
Echoing Sanders' private comments to staffers, Mulvaney said the leak was created to hurt Sadler and "completely ignored the harm it would do to the McCain family, which is doubly inconsiderate". This has left him in a bad state and he sought the comfort of his family and friends at his personal estate for the past few months.